Creating a smooth flat circle?

Questions & Answers
1

Hey there.
I’m new to the Unity scene, but I’ve been programming for a while. I’m trying to create a simple test where you can click a 2D Circle. Super simple. However, when I try to make a flat circle to click, I run in to problems. I didn’t want to use image sprites, so I initially used a flat cylinder seen from the top. It looked fine and I could use whatever collider I needed, but when I scaled it up I noticed that it seems to have a really low level of detail. See this screenshot for example:

alt text

I almost wouldn’t call it round. I feel like I’m missing something really obvious here, but when i googled it, no solutions came up. So, what can I do to increase the polygon count? And is there a better way to create a simple 2D circle?

Thank you.

4

Creates a ‘circle’-mesh with radius 0.5 and variable number of circle points:

public void MakeCircle(int numOfPoints)
{
    float angleStep = 360.0f / (float)numOfPoints;
    List<Vector3> vertexList = new List<Vector3>();
    List<int> triangleList = new List<int>();
    Quaternion quaternion = Quaternion.Euler(0.0f, 0.0f, angleStep);
    // Make first triangle.
    vertexList.Add(new Vector3(0.0f, 0.0f, 0.0f));  // 1. Circle center.
    vertexList.Add(new Vector3(0.0f, 0.5f, 0.0f));  // 2. First vertex on circle outline (radius = 0.5f)
    vertexList.Add(quaternion * vertexList[1]);     // 3. First vertex on circle outline rotated by angle)
    // Add triangle indices.
    triangleList.Add(0);
    triangleList.Add(1);
    triangleList.Add(2);
    for (int i = 0; i < numOfPoints - 1; i++)
    {
        triangleList.Add(0);                      // Index of circle center.
        triangleList.Add(vertexList.Count - 1);
        triangleList.Add(vertexList.Count);
        vertexList.Add(quaternion * vertexList[vertexList.Count - 1]);
    }
    Mesh mesh = new Mesh();
    mesh.vertices = vertexList.ToArray();
    mesh.triangles = triangleList.ToArray();               
}
3

You could get on a modelling program and do it yourself, honestly there’s not much you can do other than sprites/textures and custom mesh’s. You might be able to change the camera from Perspective mode to Orthographic then move it along the Y axis, but I don’t know if that will change the quality, I mean you won’t see all th lines if the cylinder is further away. Also, About the only way to make a 2d circle properly in Unity 2D is sprites.

2

Use sphere?